UKIP may be on course to make historic parliamentary general election breakthrough in Thanet South

UKIP could be on course to make its parliamentary breakthrough in Thanet South, according to fresh polling that puts the party ahead of the Conservatives by a small margin.

The seat is hotly tipped to be where Nigel Farage, the party leader, will stand.Polls conducted by Lord Ashcroft suggest UKIP support is at 33% in the seat, ahead of both the Conservatives and Labour.

The poll of 14,000 voters in 14 marginal Tory-held seats with Labour in second place was conducted between 18 June and 16 July.

It found the Conservatives down one point since the spring to 30%, when the seats were last surveyed. Labour were down three points to 27% and UKIP up five points to 33%.

The poll also indicated UKIP has picked up support from Labour voters in the east Kent seat.

Commenting on the results, Lord Ashcroft said the national share of the vote for each party was not necessarily a reliable guide and described the result for Thanet South as striking.

“We will see whether the party can sustain this level of support in these constituencies for another ten months. But with Nigel Farage planning to concentrate his party’s resources in just 25 targets, UKIP’s impact is likely to be felt in a series of local contests to which their headline vote share may bear little relation.”

The Conservatives recently selected the former UKIP member Craig Mackinlay as its candidate for the seat after the current MP Laura Sandys announced she was to stand down.

Mr Mackinlay said it would be “rather silly” for Mr Farage to stand against him, given that he shared the same views about Europe.

UKIP said the poll was further evidence of its support in an area in which it now has seven county councillors.

A party spokesman said: “This poll confirms that Thanet South will be a key target seat for UKIP and we will be fielding a very strong candidate in the constituency.”